Redundant PC system

Abstract

A redundant PC system includes a plurality of redundant PCs which is to be connected through a network. Each of the redundant PCs includes hardware on which an interface for connection to the network is mounted and a host OS configured to operate on the hardware. The host OS is provided with a virtualization unit, and a redundant unit and a real-time communication unit, the redundant unit and the real-time communication unit being configured to operate as separate processes independent of the virtualization unit. The redundant unit is configured to perform a control monitoring for making a PC redundant via a universal interface.

What is claimed is: 
     
       1. A redundant process control system comprising:
 a plurality of redundant personal computers (PCs) configured to be connected through first and second control networks, 
 wherein each of the redundant PCs includes:
 hardware on which a first interface for connection to the first control network, a second interface for connection to the second control network, and a third interface for connection to equalizing bus are mounted, and 
 a host operating system (OS) configured to operate on the hardware, 
 
 wherein each host OS includes:
 a virtualization unit configured to operate a guest operating system (OS) and application software, 
 a redundant unit configured to transmit equalization information including a snapshot of a memory of a virtual device of the virtualization unit to another redundant PC of the plurality of redundant PCs via the equalizing bus, detect an abnormality in the redundant PC during operation, and, with the redundant unit of the another redundant PC, switch a control right from the redundant PC to the another redundant PC during which the guest OS and the application software of the another redundant PC is started using the equalization information already transmitted to the another redundant PC, based on the detected abnormality, and 
 a real-time communication unit configured to perform real-time communication which guarantees that a certain processing is performed within a defined time period required in the process control system, transmit or receive communication packets in the first control network or the second control network and switch from the first control network to the second control network when an abnormality is detected in the first control network, and 
 
 wherein in each of the redundant PCs, the redundant unit, the virtualization unit, and the real-time communication unit are configured to operate as separate processes independent of one another. 
 
     
     
       2. The redundant process control system according to  claim 1 , wherein in each of the redundant PCs, the redundant unit and the real-time communication unit are exclusively allotted with a central processing unit (CPU) resource of the hardware, respectively. 
     
     
       3. The redundant process control system according to  claim 1 , wherein the redundant PC system configures a plant control system configured to control a plant. 
     
     
       4. The redundant process control system according to  claim 1 , wherein the redundant unit is further configured to perform diagnosis of an operation state of the hardware and the third interface of the redundant PC, to transmit a diagnosis packet to the another redundant PC via the equalization bus, and to receive another diagnosis packet from the another redundant PC via the equalization bus. 
     
     
       5. The redundant process control system according to  claim 1 , wherein the hardware of each redundant PC includes a multicore CPU, and in each of the redundant PCs, the real-time communication unit switching from the first control network to the second control network and the redundant unit switching the control right are allocated to respective CPU cores of the multicore CPU. 
     
     
       6. The redundant process control system according to  claim 1 , wherein the redundant unit is connected to a redundancy management tool via an information network, wherein the redundancy management tool is configured to switch the control right. 
     
     
       7. The redundant process control system according to  claim 1 ,
 wherein each of the first interface, the second interface and the third interface is an universal interface. 
 
     
     
       8. The redundant process control system according to  claim 1 , wherein the real-time communication unit is configured to exchange diagnosis packets with the real-time communication unit of the another redundant PC to check if the first control network is abnormal. 
     
     
       9. A communication device including a host operation system (OS) operated on a hardware on which a first network interface, a second network interface, and a third network interface are implemented,
 wherein the communication device is connected to a first control network via the first network interface and a second control network via the second network interface, and is connected to an equalization bus via the third network interface, in order to perform redundancy with another communication device, 
 wherein the host OS includes:
 a virtualization unit configured to operate a guest operating system (OS) and application software, 
 a real-time communication unit configured to perform real-time communication which guarantees a certain processing is performed within a defined time period required in a process control system, transmit or receive communication packets in the first control network or the second control network and switch from the first control network to the second control network when an abnormality is detected in the first network, and 
 a redundant unit configured to:
 transmit equalization information including a snapshot of a memory of a virtual device of the virtualization unit to the another communication device via the equalizing bus, 
 detect an abnormality in the communication device during operation, and 
 with a redundant unit of the another control device, switch a control right from the communication device to the another communication device during which a guest OS and application software of a host OS of the another communication device is started using the equalization information already transmitted to the another communication device, based on the detected abnormality, and 
 
 
 wherein the virtualization unit, the real-time communication unit and the redundant unit are configured to operate as separate processes independent of one another. 
 
     
     
       10. The communication device according to  claim 9 , wherein
 the redundant unit is further configured to perform diagnosis of an operation state of the hardware and the third network interface, to transmit a diagnosis packet to the another communication device via the equalization bus, and to receive another diagnosis packet from the another communication device via the equalization bus. 
 
     
     
       11. The communication device according to  claim 9 , wherein
 the real-time communication unit is further configured to switch from the first control network to the second control network when an abnormality is detected in the first control network. 
 
     
     
       12. The communication device according to  claim 11 , wherein the hardware of the communication device includes a multicore CPU, and wherein the real-time communication unit is configured to switch from the first control network to the second control network when an abnormality is detected in the first control network. 
     
     
       13. The communication device according to  claim 9 , wherein the communication device configures a plant control system configured to control a plant.